TASK 1.2b

MINIATURE TRAILING EDGE EFFECTORS FOR ROTORCRAFT APPLICATIONS

PRINCIPAL INVESTIGATORS

GEORGE LESIEUTREMARK MAUGHMER

MICHAEL KINZEL

MICHAEL THIEL

GRADUATE RESEARCH ASSISTANTS

GARY KOOPMANN

EARL DUQUE

BACKGROUND:

“REAL” GURNEY FLAPS

Gurney flap

Wing trailing-edge

BACKGROUND

• MINIATURE TRAILING-EDGE EFFECTORS (MiTEs)- MOVABLE TABS, PARTIAL SPAN- CONSIDERED BY VanDam, Eaton, others

• MiTEs HAVE POTENTIAL TO IMPROVE- ROTOR PERFORMANCE

• INCREASE MAX LIFT TO REDUCE RETREATING-BLADE STALL• REDUCE COMPRESSIBILITY EFFECTS ON ADVANCING SIDE

- VIBRATION CONTROL• SPANWISE & AZIMUTHAL LIFT DISTRIBUTIONS

TECHNICAL BARRIERS• ACTUATION (4/REV => 20 Hz FREQ.)• DYNAMIC PERFORMANCE NOT UNDERSTOOD• ROTOR PERFORMANCE EFFECTS

Active MiTE

Wing trailing-edge

Dist. from TE

Var

iabl

e H

eigh

t

OBJECTIVES

EXPLORE UTILITY OF ACTIVE GURNEY FLAPS

APPROACHES:

• AERODYNAMIC UNDERSTANDING:• EXPERIMENTAL: 2D STATIC / DYNAMIC• NUMERICAL: 2D STATIC / DYNAMIC

• POTENTIAL FOR ROTORCRAFT:• FLIGHT PERFORMANCE – IMPROVED PREDICTION METHODS

• IMPLEMENTATION: • ACTUATION

EXPECTED RESEARCH RESULTS:

• AERODYNAMIC EFFECTS OF SIZE AND LOCATION

• BETTER UNDERSTANDING OF GURNEY FLAP PHYSICS

• DETERMINE EFFECTS ON ROTOR PERFORMANCE

• DEVELOP VIABLE ACTUATION METHODS

• OBTAIN DYNAMIC WIND-TUNNEL DATA

EXPERIMENT: TRANSITION FIXED AT 5%c

EXPERIMENT: GURNEY LOCATION AND SIZE

GF HEIGHT0.005c0.01c0.02c

NUMERICAL INVESTIGATION: CFD STREAKLINES

NUMERICAL INVESTIGATION: CFD STREAKLINES

AERODYNAMIC MODELING OF MiTES:

, , c ( , ) = c ( ')l GF l GFM

' Stall

Stall Stall

• MACH NUMBER AERO. EFFECTS FOR A GURNEY FLAP

• CONSISTENT WHEN CONSIDERING ’

AERODYNAMIC MODELING OF MiTES:

INDICIAL RESPONSE AND HARIHARAN-LEISHMAN UNSTEADY FLAPPED AIRFOIL MODEL

• AVERAGED INDICIAL RESPONSE IS SIMILAR TO PLAIN FLAP

• ALLOW THE INVESTIGATION OF UNSTEADY PLAIN-FLAPPED AIRFOIL THEORIES

AERODYNAMIC MODELING OF MiTES:

UNSTEADY FLAPPED AIRFOIL MODEL APPLIED TO MiTES

k=0.14, M=0.1, =0deg k=0.5, M=0.6, =0deg

AERODYNAMIC MODELING OF MiTES:

UNSTEADY FLAPPED AIRFOIL - DYNAMIC STALL MODEL

DYNAMIC STALL MODELUNSTEADY FLAPPED AIRFOIL MODEL

CFD – OVERFLOW2

EFFECT OF MiTE POSITION:

(a) xMiTE=1.0c

(b) xMiTE=0.9c

• VORTEX STREET FORMS CREATES HIGH FREQ. OSCILLATIONS

• TRAILING EDGE PLACEMENT AGREES WELL WITH THEODORSEN CIRCULATORY THEORY

• UPSTREAM PLACEMENT HAS LARGE DYNAMIC LOADS AND INCREASED LAGS

(a)

(b)

PERFORMANCE ANALYSIS: OPTIMAL DEPLOYMENT STRATEGY

REASONABLE FOR STEADY ASSUMPTIONS, BUT NOT WHEN UNSTEADY AERO. AND DYN. STALL ARE CONSIDERED

PERFORMANCE ANALYSIS: FORWARD FLIGHT

PERFORMANCE ANALYSIS: MiTE DEPLOYMENT

PERFORMANCE ANALYSIS: FORWARD FLIGHT WITH VARIATIONS IN AIRFOIL TRANSITION RADIUS

NOTE: DEPLOYMENT IS SCHEDULED TO

MINIMIZE PITCHING MOMENT

PERFORMANCE ANALYSIS: EFFECT OF MiTE DRAG TO PERFORMANCE ENHANCEMENT

ACTUATOR DESIGN

• DESIGN FOR AERODYNAMIC BENEFITS– OPERATING FREQUENCIES OF 4 – 5 Hz

• APPLY TO A VR-12 AIRFOIL– HEIGHT: 0.01c

– LOCATION: 0.9c

Fig. from Johnson, W., Helicopter Theory

AERODYNAMIC FORCE ON THE FLAP

• Re = 4x106

• M = 0.45• HEIGHT: 0.02c• PER UNIT SPAN• ONLY DRAG

ACCURATELY MODELED

ACTUATOR ISSUES

• DESIGN CONSIDERATIONS• SIZE CONSTRAINTS• TOTAL WEIGHT• FREQUENCY REQUIREMENTS• CENTRIFUGAL FORCES

• ACTUATION METHODS UNDER CONSIDERATION• LINEAR DC ACTUATORS (VOICE COILS)• PIEZOELECTRIC• ROTARY/STEPPER MOTORS

VR-12 AIRFOIL

~14” CHORD

FLAP ACTUATION: AMPLIFIED PIEZO BENDER

Fp

Mh

Piezoelectric BenderCoupler

• TAPERED PIEZO BENDER• LEVER AMPLIFIER

• REQUIREMENTS• QUASISTATIC DISP. > 0.36”

• RESONANT FREQ

• > 20 Hz (4/rev)

• MODELS• PIEZO BEAM FOR DISP.

• R-R FOR RESONANCE FREQ.

LINEAR DC ACTUATORS

• MOVING COIL (NCC)

– MORE FORCE

– HEAVIER

Motion

Motion

• MOVING MAGNET (NCM)

– LESS FORCE

– LIGHTER

TESTING OF NCC ACTUATOR

- LASER VELOCIMETER USED

- BROADER FREQUENCY RANGE NEEDED

CURRENT CONCEPT

• CURRENT CONCEPT FOR NCC ACTUATOR

• LOCATE AS FAR AFT AS POSSIBLE

• SIMILAR DESIGN FOR THE NCM ACTUATOR

• OPTIMAL DIMENSIONS NEEDED

• REFINE SIMULATION MODEL

• BUILD PROTOTYPE OF NCC ACTUATOR

• TEST NCM ACTUATOR

• DEVELOP DESIGNS FOR OTHER ACTUATOR TYPES (i.e. PIEZO)

• DETERMINE COMPARISON CRITERIA

• DETERMINE OPTIMAL INPUT SIGNAL

• DEVELOP METHODS TO TEST UNDER CF LOADS

ACTUATION DESIGN - IMMEDIATE FUTURE

ACCOMPLISHMENTS

• WIND-TUNNEL MEASUREMENTS OF GURNEY FLAPS (2002)• CFD PREDICTION OF GURNEY FLAP PERFORMANCE (2003)• ACTUATION CONCEPTS EXPLORED (2002)• DYNAMIC CFD CALCULATIONS (2003-2004)• ROTOR PERFORMANCE ANALYSIS (2003-2004)

– INCLUDE DYNAMIC STALL MODEL– CONSIDER UNSTEADY MiTE MODEL

• INVESTIGATE MODELING UNSTEADY AERO. OF MiTES (2004)• MORE EXTENSIVE ACTUATION METHODS EXPLORED (2004-2005)

– LINEAR DC ACTUATORS– PIEZOELECTRIC

• BUILD MODELS OF ACTUATION SYSTEMS

• WIND-TUNNEL VERIFICATION OF ACTUATION METHODS

• EXTEND ACTUATION DESIGN TO FULL-SCALE ROTOR BLADE

2005-2006 PLANS

PUBLICATIONS• Maughmer, M., Lesieutre, G., Thepvongs, S., Anderson, W, Kinzel, M.,

“Miniature Trailing-Edge Effectors for Rotorcraft Applications”, AHS 59th Forum, Phoenix, AZ, May 2003.

• Kinzel, M., “Miniature Trailing-Edge Effectors for Rotorcraft Applications,” Mindbend 2004 Student Conference, University Park, PA, April 2004.

• Kinzel, M.P., “Miniature Trailing-Edge Effectors for Rotorcraft Applications,” M.S. Thesis, Dept. of Aerospace Eng., Penn State University, University Park, PA, 2004.

• Kinzel, M.P, Maughmer, M.D, Lesieutre, G.L, Duque, E.P.N, "Numerical Investigation of Miniature Trailing-Edge Effectors on Static and Oscillating Airfoils," AIAA Paper No. 2005-1039, 2005.

• Thiel, M., “Actuation of an Active Gurney Flap for Rotorcraft Applications,” Mindbend 2005 Student Conference, University Park, PA, April 2005.

• Maughmer, M., Lesieutre, G., Kinzel, M., “Miniature Trailing-Edge Effectors for Rotorcraft Performance Enhancement”, AHS 61th Forum, Grapevine, TX, June 2005.

FUTURE RESEARCH NEEDS• DEVELOPMENT OF UNSTEADY AERO. MODELS FOR THE UPSTREAM

PLACEMENT OF MITES• DYNAMIC WIND-TUNNEL DATA • COMPREHENSIVE ROTOR PERFORMANCE / APPLICATION ANALYSES• HIGH-FREQUENCY ACTUATION DESIGN• MITE SPECIFIC AIRFOIL DESIGN• OTHER POTENTIAL BENEFITS OF MITES FOR ROTORCRAFT

MiTE SCHEDULETASKS 2001 2002 2004 2005

STAGE ONE

WT TEST WITH FIXED GURNEY FLAP

CFD SOLUTIONS (FLUENT)

MODEL ACTUATOR DESIGN

STAGE TWO

TRANSONIC CFD SOLUTIONS

ROTOR PERFORMANCE

SPECAILIZED CFD (OVERFLOW)

STAGE THREEDEVELOP FULL SCALE ACTUATORS

DYNAMIC WT TESTING

SHORT TERMLONG TERMCOMPLETE

2003 2006